In a saddle-riding vehicle disclosed in patent literature 1, a laterally-divided fuel tank is provided above a main frame which extends rearward from a head pipe so as to straddle the main frame. This fuel tank protrudes downward greatly so as to ensure a great capacity and is constructed to cover the engine from sides thereof. In addition, patent literature 1 discloses a construction in which a front portion and a lower portion of the engine is covered by a skid guard (an under guard) and sides of the fuel tank are partially covered by a front cowl.